Johannesburg is the economic hub of South Africa. It is also South Africa's most populous city with a population of 5,783,000 in 2020.
Johannesburg was founded in 1886 as a gold mining village and in 1928 it became the biggest city in South Africa. Since then it has undergone drastic and ongoing rapid urbanisation. The original highveld grassland has been transformed into a sprawling metropolis. This land transformation process included the widespread planting of exotic and indigenous ornamental trees along streets and in gardens and parks.
The massive tree planting undertaking began at the end of the 19th century as a response to the air pollution and dust resulting from the city’s intensive gold mining. Wood from the trees was also used to support mine shafts and excavations. For this reason, fast growing trees such as Eucalyptus species and Black Wattle from Australia, and Jacarandas from South America were planted. The British colonists also planted several tree species, that they were familiar with, including Plane trees, Oak trees, and Ash trees.
All of this tree planting led to Johannesburg being widely considered as one of the largest manmade forests in the world. About 16.1% of the city is covered by trees. Due to the nature of Johannesburg’s development, there is a disparity between the tree cover in the historically wealthier northern suburbs (24.2% tree cover), and the historically poorer southern suburbs (6.7% tree cover).
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Additionally, the densely populated City of Johannesburg displays living conditions ranging from wealthy ‘westernised’ suburbs to informal settlements with little service delivery (Howes & Reynolds, 2021). This extreme range of socio-economic conditions, along with the unequal distribution of urban green spaces, makes Johannesburg an interesting and unique case study for urban ecology.